1. Field of the Invention
The invention relates to a control device for activating recording elements in a recording device for the recording of characters which are composed of dot-shaped or line-shaped elements which are arranged in rows and columns on a record carrier, said recording device comprising a member which can be driven in front of the record carrier in a row direction, said member comprising at least one group of recording elements which are adapted to record a character element, each group comprising a number of recording elements which at least equals the maximum number of rows of character elements in a character, at least one recording element being associated with each row within a group such that each time a predetermined row jump or advance is present between successive recording elements of a group, and between successive recording elements, at a transition between successive groups, the recording elements being staggered in the row direction in that between successive recording elements of a group and between successive recording elements, at a transition between successive groups, each time a predetermined columm advance or jump is present whereby, in the case of the presence of a plurality of groups of said groups succeed each other in the line direction, said control device furthermore comprising a buffer memory for receiving the characters to be recorded together on a row, a character generator having a first sub-address input which is connected to an output of the buffer memory for the general addressing of a character, a dot memory having an input which is connected to an output of the character generator for storing character element data and having outputs which are suitable to supply control signals for the relevant recording elements, so that per displacement of said movable member over one column distance, and each time per recording element, a character element is supplied, measuring means being provided for supplying movement signals and position signals concerning said member in order to activate, per column displacement thereof, said dot memory through a connection between an output of said measuring means and an input of said dot memory, a further output of said measuring means being connected to an input of said buffer memory in order to form, at the start of a line to be recorded by way of a movement of said member in a first direction, a starting address for the buffer memory and a starting condition signal for said character generator by means of a chaining unit, an input of which is connected to an output of said measuring means, outputs thereof being connected to an address input of said buffer memory, and a second sub-address input of said character generator for supplying a row or column address for a character generally addressed by said first sub-address, said chaining unit containing the data of said row advances and column advances and a return connection for serially forming for all successive recording elements, between the presence of said member in two successive column positions, on the basis of said starting condition signal and the relevant row advances and column advances, an address which is composed of first and second sub-address signals, in said character generator, assisted by the first sub-address signal supplied by said buffer memory, and to regenerate said starting condition signal at the end of the series with an additional unit of column advance in said first direction until a detection circuit detects an end condition signal so that a line of characters has been printed.
2. Description of the Prior Art
A control device for a matrix printer of this kind is disclosed in U.S. Pat. No. 4,024,506, which is incorporated herein by reference. Known recording devices are subdivided mainly into two categories. One category includes high-speed printers comprising a large number of printing elements which instantaneously produce a character and which are arranged, for example, on a drum which rotates at a high speed tangentially to the paper. On the other hand, slower devices are known in which a next column of a character is recorded, by a series of printing styli which are arranged in the column direction. The recording device disclosed in said patent combines serial and parallel methods, so that a device which is intermediate as regards price and performance is obtained. Recording devices of this kind can be connected to an output of a computer and form so-called "hard copies" which can be temporarily stored and which can be read again at a later stage, if necessary, by the users, or can be applied to an optical reader for renewed input into a computer memory or for other processing or use. The dimensions of the character field (font) to be used constitute an important design parameter. On the one hand, large characters are properly legible to humans and can be easily recognized by a reader. On the other hand, in order to save on the cost of paper, to save storage space and, moreover, to increase the ease of handling, a small paper format is desired, for example, the format DIN A4 which measures approximately 296.times.209 mm. However, a large number of characters per line are still required.